CVE-2026-33748
Description
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, insufficient validation of Git URL fragment subdir components may allow access to files outside the checked-out Git repository root. Possible access is limited to files on the same mounted filesystem. The issue has been fixed in version v0.28.1 The issue affects only builds that use Git URLs with a subpath component. As a workaround, avoid building Dockerfiles from untrusted sources or using the subdir component from an untrusted Git repository where the subdir component could point to a symlink.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | affected | |
| debian | bullseye | affected | |
| debian | forky | affected | |
| debian | sid | affected | |
| debian | trixie | affected | |
| sles | affected | |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Go | github.com/moby/buildkit | <0.28.1 | 0.28.1 |
References
- https://security-tracker.debian.org/tracker/CVE-2026-33748
- https://github.com/moby/buildkit/security/advisories/GHSA-4vrq-3vrq-g6gg
- https://nvd.nist.gov/vuln/detail/CVE-2026-33748
- https://docs.docker.com/build/concepts/context/#url-fragments
- https://github.com/moby/buildkit
- https://github.com/moby/buildkit/releases/tag/v0.28.1
- https://www.suse.com/security/cve/CVE-2026-33748.html
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.